The invention relates to a portable or traveling transporting device for winding material, particularly a hose truck.
Transporting devices of this type are e.g. used in the garden sector as portable or travelling hose trucks. They have a frame normally provided with a handle or the like and on which is provided a travelling mechanism for moving the transporting device on a ground surface and at least one winding drum for winding up the winding material, e.g. a hose or cable. The travelling mechanism, which normally has several ground wheels or rolls, comprises at least one rotary element rotatable by the movement of the transporting device, i.e. driven by the advance or return movement of said transporting device and a force transfer mechanism for making a drive connection between said rotary element and the winding drum. Such a force transfer means, e.g. constructed as a gear, makes it possible to couple the advance or return movement of the transporting device with the winding movement of the winding drum, so that e.g. during the movement of the transporting device a hose is automatically wound on or off by the winding roll driven in rotary manner.
A hose truck in which a hose drum is drivable by means of a gear through the rotation of ground wheels is known from DE 43 04 127. In the case of this hose truck the diameters of the ground wheels connected to the gear, the gear ratio and the winding drum diameter are so matched to one another that when the winding drum is empty the travel distance covered substantially corresponds to the winding up length brought about by the rotation of the winding roll. As a result an exact single-layer rolling up of the hose is made possible and simultaneously a horizontally moving hose guide is driven, which ensures that the hose during each drum rotation is precisely and adequately placed on the previously wound portion. A multilayer winding does not take place.
The problem of the invention is to create a portable winding material transporting device of the aforementioned type in such a way as to permit a problemfree winding up and off of even considerable winding material lengths.
A transporting device of the aforementioned type constructed according to the invention and in particular in the form of a hose truck is so constructed that in the case of a single or multiple layer winding up of winding material a limited winding force can be exerted thereon. The winding force is automatically set in such a way that there are no excessive tensile forces stretching or straining the hose or other winding material over a considerable distance. As a result the winding material is protected during the winding process and at the same time a tight and consequently compact or space-saving winding is possible. The limited winding force is made available substantially independently of the winding diameter, so that it is provided both with a single-layer winding and also when there are several winding layers. Thus, large winding material lengths can be housed on a winding drum of limited width. The magnitude of the limited winding force is appropriately dimensioned in such a way that on the one hand the formation of loose winding loops is avoided and on the other the possibly hollow winding material is not compressed or excessively loaded in any other way.
For this purpose, according to a preferred further development the force transfer means between the rotary element and the winding drum has at least one automatic torque limiting device for limiting the torque transferred by the rotary element to the winding drum. Thus, without any external intervention on the part of an operator, there can automatically be a loosening or interruption of the drive coupling between the travelling mechanism and the winding drum as soon as the movement of the transporting device provides more torque than is needed for maintaining the limited winding force. In particular, within the force transfer path from the travelling mechanism to the winding drum can be provided a type of slip clutch, which can e.g. ensure that in the presence of larger hose layer diameters and/or with a multilayer winding the travelling mechanism or drive side can lead compared with the winding drum rotation, but without the force transfer being completely eliminated.
The torque limiting means can have any appropriate construction ensuring said slip clutch function. According to a further development, which is in particular characterized by simple construction, robustness and reliable operation, the torque limiting means has a coupling part in the form of a coupling gear wheel and another rotary coupling part with at least one spring-loaded driving element, which is constructed for engagement in the teeth of the coupling gear wheel. Thus, below a torque limit, a positive driving of both coupling parts is brought about, whereas on exceeding the torque limit the driving element, counter to the spring tension, leaves the positive engagement position, so as to permit a mutual relative rotation of the coupling parts. Appropriately the driving element is constructed as a roll or rolling body, e.g. in the manner of a roller, so that a low-wear coupling operation is aided. Preferably there are several driving elements uniformly distributed along the coupling gear wheel circumference in order to on the one hand ensure a reliable engagement and on the other to assist an automatic centring of the coupling gear wheel, which can also be independently placed in a guide.
In the case of several, e.g. four driving elements, the tooth system of the coupling gear wheel can have a plurality of teeth which cannot be divided by the number of driving elements. As a result always only part of the driving elements are in complete engagement with the tooth system and the notch step width on notching through the winding drum is reduced by a factor of e.g. two compared with the circumferential spacing of neighbouring teeth, so that even with coarse teeth a fine notching can be achieved.
In an embodiment explained in greater detail in conjunction with the drawings, the tooth system of the coupling gear wheel is asymmetrical with respect to a rotation direction reversal and preferably the teeth of the tooth system have a steep side and a side which is less steep. As will be explained hereinafter, as a result e.g. with a faster relative rotation of the coupling parts it is possible to avoid a jumping of the driving elements and a resulting reduction of the driving force and additionally an easier manual rotation of the winding drum in the winding up direction can take place with reduced force expenditure.
As a result of the force transfer means in the case of a transporting device constructed as a hose truck it is possible to bring about an automatic winding up of the hose in the travel direction of the hose truck towards a laid out hose portion. According to a further development the force or torque-transferring coupling between the travelling mechanism and the winding drum can, if necessary, be eliminated. For this purpose the force transfer means has a preferably manually operable clutch for the as desired cancellation or making of the drive connection between the rotary element and the winding drum and which can e.g. be operated by means of a clutch lever. The possibility of cancelling out the drive connection is e.g. advantageous if the hose or other winding material is to be unwound manually from the winding drum with the transporting device stationary or if the transporting device is to be moved solely for transportation without winding drum rotation.
Apart from numerous possibilities known to the expert for implementing such a clutch, preference is given to a variant in which the clutch has at least one coupling gear wheel positioned between a drive or travelling mechanism-side gear wheel and a drive side gear wheel, which as a result of the displacement of its rotation axis can, as desired, be engaged or disengaged with respect to at least one of the adjacent gear wheels. Such clutches are particularly advantageously implementable in a flat gear. If the rotation axis of the coupling gear wheel is pivotable about the rotation axis of its neighbouring gear wheels, the coupling gear wheel remains engaged with said gear wheel even in the uncoupled state, so that a following coupling can be performed in a particularly reliable manner.
It is also possible for the coupling permitted by the force transfer means between the travelling mechanism and the winding roll to act in both movement directions of the transporting device, so that the winding drum can be driven both in the winding up and the unwinding direction. However, preferably, the force transfer means is constructed for a drive connection between the rotary element and the winding drum only acting in the winding up direction of said drum. In a further development this is implemented in that the force transfer means has between the rotary element of the travelling mechanism and the winding drum at least one freewheel device, particularly in the manner of a ratchet freewheel. Thus, even in the absence of a disengageable clutch, an easy manual unwinding of winding material would be possible even with the transporting device stationary.
In preferred further developments the winding characteristics of the transporting device are significantly aided by a pressing device connected upstream of the winding drum in the movement direction on winding up for pressing winding material located on the ground surface onto the latter. As a result of the thus permitted easy pressing of e.g. a hose to be wound up on a lawn surface a slipping of the hose on the ground is largely avoided, so that e.g. a hose laid out in curves is not drawn tight whilst shortening said curves. This makes it possible to obtain an easy, continuous winding up without rotation speed jumps on the part of the winding roll. Through the obviating of the tension on the hose, it is also possible to avoid a force action on a tap or faucet connecting piece or a control device located at the hose connection, such as e.g. an automatic watering control device, so that there is no damage or destruction to such parts, which can easily take place when a tensile force acts via the hose. Appropriately the pressing device extends essentially over the entire width of the transporting device, so as to ensure an adequate pressing of the winding material, particularly in curves. Although the pressing can be brought about by runners, brushes, etc., the pressing device preferably has as the pressing member at least one roll body for rolling on the laid out winding material, so as to permit an easy relative movement between the pressing device and the winding material. the compressive force acting in the ground surface direction necessary for a pressing action is preferably at least partly provided by the transporting device, so that for this purpose no force need be expended by an operator. Thus, e.g. the pressing device can be so positioned relative to the winding drum that at least part of the winding drum weight acts on the pressing device. An embodiment in which the pressing device is formed by the front rolls of a travelling mechanism will be described relative to the embodiments.
An upstream connected pressing device of the aforementioned type can be advantageous, independently of the slip clutch function shown, in other hose trucks or similar transporting devices not in accordance with the invention. A pressing roll or a similar pressing member can also be appropriate in the case of conventional hose trucks with moving unwinding of the hose from the hose drum, because as a result e.g. the aforementioned disadvantages are avoidable, namely the stretching of a hose laid out in curves and/or a disadvantageous force action on a tap or faucet connection.
These and further features can be gathered from the claims, description and drawings and the individual features, either singly or in the form of subcombinations, can be implemented in an embodiment of the invention and in other fields and can represent advantageous constructions.